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    An Overview of Content Analysis

    Steve Stemler

    Yale University

    Content analysis has been defined as a systematic, replicable technique for compressing

    many words of text into fewer content categories based on explicit rules of coding (Berelson,

    1952; GAO, 1996; Krippendorff, 1980; and Weber, 1990). Holsti (1969) offers a broad

    definition of content analysis as, "any technique for making inferences by objectively andsystematically identifying specified characteristics of messages" (p. 14). Under Holsti s

    definition, the technique of content analysis is not restricted to the domain of textual

    analysis, but may be applied to other areas such as coding student drawings (Wheelock,

    Haney, & Bebell, 2000), or coding of actions observed in videotaped studies (Stigler,

    Gonzales, Kawanaka, Knoll, & Serrano, 1999). In order to allow for replication, however,

    the technique can only be applied to data that are durable in nature.

    Content analysis enables researchers to sift through large volumes of data with relativeease in a systematic fashion (GAO, 1996). It can be a useful technique for allowing us to

    discover and describe the focus of individual, group, institutional, or social attention(Weber, 1990). It also allows inferences to be made which can then be corroborated using

    other methods of data collection. Krippendorff (1980) notes that "[m]uch content analysis

    research is motivated by the search for techniques to infer from symbolic data what would

    be either too costly, no longer possible, or too obtrusive by the use of other techniques" (p.

    51).

    Practical Applications of Content Analysis

    Content analysis can be a powerful tool for determining authorship. For instance, one

    technique for determining authorship is to compile a list of suspected authors, examine

    their prior writings, and correlate the frequency of nouns or function words to help build acase for the probability of each person's authorship of the data of interest. Mosteller andWallace (1964) used Bayesian techniques based on word frequency to show that Madison

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    was indeed the author of the Federalist papers; recently, Foster (1996) used a more holistic

    approach in order to determine the identity of the anonymous author of the 1992 bookPrimary Colors.

    Content analysis is also useful for examining trends and patterns in documents. For

    example, Stemler and Bebell (1998) conducted a content analysis of school missionstatements to make some inferences about what schools hold as their primary reasons for

    existence. One of the major research questions was whether the criteria being used to

    measure program effectiveness (e.g., academic test scores) were aligned with the overallprogram objectives or reason for existence.

    Additionally, content analysis provides an empirical basis for monitoring shifts in public

    opinion. Data collected from the mission statements project in the late 1990s can be

    objectively compared to data collected at some point in the future to determine if policy

    changes related to standards-based reform have manifested themselves in school mission

    statements.

    Conducting a Content Analysis

    According to Krippendorff (1980), six questions must be addressed in every content

    analysis:

    1) Which data are analyzed?

    2) How are they defined?

    3) What is the population from which they are drawn?

    4) What is the context relative to which the data are analyzed?

    5) What are the boundaries of the analysis?

    6) What is the target of the inferences?

    At least three problems can occur when documents are being assembled for contentanalysis. First, when a substantial number of documents from the population are missing,the content analysis must be abandoned. Second, inappropriate records (e.g., ones that do

    not match the definition of the document required for analysis) should be discarded, but arecord should be kept of the reasons. Finally, some documents might match the

    requirements for analysis but just be uncodable because they contain missing passages orambiguous content (GAO, 1996).

    Analyzing the Data

    Perhaps the most common notion in qualitative research is that a content analysis simply

    means doing a word-frequency count. The assumption made is that the words that are

    mentioned most often are the words that reflect the greatest concerns. While this may be

    true in some cases, there are several counterpoints to consider when using simple word

    frequency counts to make inferences about matters of importance.

    One thing to consider is that synonyms may be used for stylistic reasons throughout adocument and thus may lead the researchers to underestimate the importance of a concept

    (Weber, 1990). Also bear in mind that each word may not represent a category equallywell. Unfortunately, there are no well-developed weighting procedures, so for now, using

    word counts requires the researcher to be aware of this limitation. Furthermore, Weber

    reminds us that, "not all issues are equally difficult to raise. In contemporary America itmay well be easier for political parties to address economic issues such as trade and

    deficits than the history and current plight of Native American living precariously on

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    reservations" (1990, p. 73). Finally, in performing word frequency counts, one should bear

    in mind that some words may have multiple meanings. For instance the word "state" could

    mean a political body, a situation, or a verb meaning "to speak."

    A good rule of thumb to follow in the analysis is to use word frequency counts to identify

    words of potential interest, and then to use a Key Word In Context (KWIC) search to testfor the consistency of usage of words. Most qualitative research software (e.g., NUD*IST,

    HyperRESEARCH) allows the researcher to pull up the sentence in which that word was

    used so that he or she can see the word in some context. This procedure will help tostrengthen the validity of the inferences that are being made from the data. Certainsoftware packages (e.g., the revised General Inquirer) are able to incorporate artificial

    intelligence systems that can differentiate between the same word used with two different

    meanings based on context (Rosenberg, Schnurr, & Oxman, 1990). There are a number of

    different software packages available that will help to facilitate content analyses (see

    further information at the end of this paper).

    Content analysis extends far beyond simple word counts, however. What makes the

    technique particularly rich and meaningful is its reliance on coding and categorizing of the

    data. The basics of categorizing can be summed up in these quotes: "A category is a group

    of words with similar meaning or connotations" (Weber, 1990, p. 37). "Categories must be

    mutually exclusive and exhaustive" (GAO, 1996, p. 20). Mutually exclusive categories exist

    when no unit falls between two data points, and each unit is represented by only one data

    point. The requirement of exhaustive categories is met when the data language represents

    all recording units without exception.

    Emergent vs. a priori coding. There are two approaches to coding data that

    operate with slightly different rules. With emergent coding, categories are

    established following some preliminary examination of the data. The steps to

    follow are outlined in Haney, Russell, Gulek, & Fierros (1998) and will be

    summarized here. First, two people independently review the material andcome up with a set of features that form a checklist. Second, the researchers

    compare notes and reconcile any differences that show up on their initial

    checklists. Third, the researchers use a consolidated checklist to independently

    apply coding. Fourth, the researchers check the reliability of the coding (a 95%

    agreement is suggested; .8 for Cohen's kappa). If the level of reliability is not

    acceptable, then the researchers repeat the previous steps. Once the reliability

    has been established, the coding is applied on a large-scale basis. The final

    stage is a periodic quality control check.

    When dealing with a priori coding, the categories are established prior to the analysisbased upon some theory. Professional colleagues agree on the categories, and the coding is

    applied to the data. Revisions are made as necessary, and the categories are tightened up

    to the point that maximizes mutual exclusivity and exhaustiveness (Weber, 1990).

    Coding units. There are several different ways of defining coding units. The

    first way is to define them physically in terms of their natural or intuitive

    borders. For instance, newspaper articles, letters, or poems all have natural

    boundaries. The second way to define the recording units syntactically, that is,

    to use the separations created by the author, such as words, sentences, or

    paragraphs. A third way to define them is to use referential units. Referential

    units refer to the way a unit is represented. For example a paper might refer toGeorge W. Bush as "President Bush," "the 43rd president of the United States,"

    or "W." Referential units are useful when we are interested in making

    inferences about attitudes, values, or preferences. A fourth method of defining

    coding units is by using propositional units. Propositional units are perhaps

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    the most complex method of defining coding units because they work by

    breaking down the text in order to examine underlying assumptions. For

    example, in a sentence that would read, "Investors took another hit as the stock

    market continued its descent," we would break it down to: The stock market

    has been performing poorly recently/Investors have been losing money

    (Krippendorff, 1980).

    Typically, three kinds of units are employed in content analysis: sampling units, context

    units, and recording units.

    Sampling units will vary depending on how the researcher makes meaning; theycould be words, sentences, or paragraphs. In the mission statements project, the

    sampling unit was the mission statement.

    Context units neither need be independent or separately

    describable. They may overlap and contain many recording units.

    Context units do, however, set physical limits on what kind of

    data you are trying to record. In the mission statements

    project, the context units are sentences. This was an arbitrary

    decision, and the context unit could just as easily have been

    paragraphs or entire statements of purpose.

    Recording units, by contrast, are rarely defined in terms of

    physical boundaries. In the mission statements project, the

    recording unit was the idea(s) regarding the purpose of school

    found in the mission statements (e.g., develop responsible

    citizens or promote student self-worth). Thus a sentence that

    reads "The mission of Jason Lee school is to enhance students'

    social skills, develop responsible citizens, and foster

    emotional growth" could be coded in three separate recordingunits, with each idea belonging to only one category

    (Krippendorff, 1980).

    Reliability. Weber (1990) notes: "To make valid inferences from the text, it is

    important that the classification procedure be reliable in the sense of being

    consistent: Different people should code the same text in the same way" (p. 12).

    As Weber further notes, "reliability problems usually grow out of the ambiguity

    of word meanings, category definitions, or other coding rules" (p. 15). Yet, it is

    important to recognize that the people who have developed the coding scheme

    have often been working so closely on the project that they have established

    shared and hidden meanings of the coding. The obvious result is that the

    reliability coefficient they report is artificially inflated (Krippendorff, 1980). In

    order to avoid this, one of the most critical steps in content analysis involves

    developing a set of explicit recording instructions. These instructions then

    allow outside coders to be trained until reliability requirements are met.

    Reliability may be discussed in the following terms:

    Stability, or intra-rater reliability. Can the same coder get the same results try after

    try?

    Reproducibility, or inter-rater reliability. Do coding schemes

    lead to the same text being coded in the same category by

    different people?

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    One way to measure reliability is to measure the percent of agreement between raters.This involves simply adding up the number of cases that were coded the same way by the

    two raters and dividing by the total number of cases. The problem with a percentagreement approach, however, is that it does not account for the fact that raters are

    expected to agree with each other a certain percentage of the time simply based on chance(Cohen, 1960). In order to combat this shortfall, reliability may be calculated by using

    Cohen's Kappa, which approaches 1 as coding is perfectly reliable and goes to 0 when there

    is no agreement other than what would be expected by chance (Haney et al., 1998). Kappais computed as:

    where:

    = proportion of units on which the raters agree

    = the proportion of units for which agreement is expected by chance.

    Table 1 Example Agreement Matrix

    Rater 1 Marginal

    Totals

    Academic Emotional Physical

    Rater 2

    Academic .42 (.29)* .10 (.21) .05 (.07) .57

    Emotional .07 (.18) .25 (.18) .03 (.05) .35

    Physical .01 (.04) .02 (.03) .05 (.01) .08

    .50 .37 .13 1.00

    *Values in parentheses represent the expected proportions on the basis of chance associations, i.e. the jointprobabilities of the marginal proportions.

    Given the data in Table 1, a percent agreement calculation can be derived by summing the

    values found in the diagonals (i.e., the proportion of times that the two raters agreed):

    By multiplying the marginal values, we can arrive at an expected proportion for each cell

    (reported in parentheses in the table). Summing the product of the marginal values in the

    diagonal we find that on the basis of chance alone, we expect an observed agreement value

    of:

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    Kappa provides an adjustment for this chance agreement factor. Thus, for the data inTable 1, kappa would be calculated as:

    In practice, this value may be interpreted as the proportion of agreement between ratersafter accounting for chance (Cohen, 1960). Crocker & Algina (1986) point out that a value

    of does not mean that the coding decisions are so inconsistent as to be worthless,

    rather, may be interpreted to mean that the decisions are no more consistent than

    we would expect based on chance, and a negative value of kappa reveals that the observed

    agreement is worse than expected on the basis of chance alone. "In his methodological note

    on kappa in Psychological Reports, Kvalseth (1989) suggests that a kappa coefficient of

    0.61 represents reasonably good overall agreement." (Wheelock et al., 2000). In addition,

    Landis & Koch (1977, p.165) have suggested the following benchmarks for interpreting

    kappa:

    Kappa Statistic Strength of Agreement

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    Validity. It is important to recognize that a methodology is always employed in

    the service of a research question. As such, validation of the inferences made

    on the basis of data from one analytic approach demands the use of multiple

    sources of information. If at all possible, the researcher should try to have some

    sort of validation study built into the design. In qualitative research, validation

    takes the form of triangulation. Triangulation lends credibility to the findings

    by incorporating multiple sources of data, methods, investigators, or theories

    (Erlandson, Harris, Skipper, & Allen, 1993).

    For example, in the mission statements project, the research question was aimed at

    discovering the purpose of school from the perspective of the institution. In order to cross-

    validate the findings from a content analysis, schoolmasters and those making hiring

    decisions could be interviewed about the emphasis placed upon the school's mission

    statement when hiring prospective teachers to get a sense of the extent to which a

    school s values are truly reflected by mission statements. Another way to validate the

    inferences would be to survey students and teachers regarding the mission statement to

    see the level of awareness of the aims of the school. A third option would be to take a look

    at the degree to which the ideals mentioned in the mission statement are being

    implemented in the classrooms.

    Shapiro & Markoff (1997) assert that content analysis itself is only valid and meaningful to

    the extent that the results are related to other measures. From this perspective, an

    exploration of the relationship between average student achievement on cognitivemeasures and the emphasis on cognitive outcomes stated across school mission statements

    would enhance the validity of the findings. For further discussions related to the validity ofcontent analysis see Roberts (1997), Erlandson et al. (1993), and Denzin & Lincoln (1994).

    Conclusion

    When used properly, content analysis is a powerful data reduction technique. Its major

    benefit comes from the fact that it is a systematic, replicable technique for compressing

    many words of text into fewer content categories based on explicit rules of coding. It has

    the attractive features of being unobtrusive, and being useful in dealing with large

    volumes of data. The technique of content analysis extends far beyond simple word

    frequency counts. Many limitations of word counts have been discussed and methods of

    extending content analysis to enhance the utility of the analysis have been addressed. Two

    fatal flaws that destroy the utility of a content analysis are faulty definitions of categories

    and non-mutually exclusive and exhaustive categories.

    Further information

    For links, articles, software and resources see

    http://writing.colostate.edu/references/research/content/

    http://www.gsu.edu/~wwwcom/.

    References

    Berelson, B. (1952). Content Analysis in Communication Research. Glencoe, Ill: Free Press.

    Cohen, J. (1960). A coefficient of agreement for nominal scales. Educational and

    Psychological Measurement, 20, pp. 37- 46.

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    Crocker, L., & Algina, J. (1986). Introduction to Classical and Modern Test Theory.Orlando, FL: Harcourt Brace Jovanovich.

    Denzin, N.K., & Lincoln, Y.S. (Eds.). (1994). Handbook of Qualitative Research. Thousand

    Oaks, CA: Sage Publications.

    Erlandson, D.A., Harris, E.L., Skipper, B.L., & Allen, S.D. (1993).Doing Naturalistic

    Inquiry: A Guide to Methods. Newbury Park, CA: Sage Publications.

    Foster, D. (1996, February 26). Primary culprit. New York, 50- 57.

    Haney, W., Russell, M., Gulek, C., and Fierros, E. (Jan-Feb, 1998). Drawing on education:

    Using student drawings to promote middle school improvement. Schools in the Middle,7(3), 38- 43.

    Holsti, O.R. (1969). Content Analysis for the Social Sciences and Humanities. Reading, MA:

    Addison-Wesley.

    Krippendorff, K. (1980). Content Analysis: An Introduction to Its Methodology. NewburyPark, CA: Sage.

    Kvalseth, T. O. (1989). Note on Cohen s kappa.Psychological reports, 65, 223- 26.

    Landis, J.R., & Koch, G.G. (1977). The measurement of observer agreement for categorical

    data. Biometrics, 33, pp. 159- 174.

    Mosteller, F. and D.L. Wallace (1964). Inference and Disputed Authorship: The Federalist.

    Reading, Massachusetts: Addison-Wesley.

    Nitko, A.J. (1983). Educational Tests and Measurement: An Introduction. New York, NY:

    Harcourt Brace Jovanovich.

    Roberts, C.W. (Ed.) (1997). Text Analysis for the Social Sciences: Methods for Drawing

    Statistical Inferences from Texts and Transcripts. Mahwah, NJ: Lawrence Erlbaum

    Associates.

    Rosenberg, S.D., Schnurr, P.P., & Oxman, T.E. (1990). Content analysis: A comparison of

    manual and computerized systems. Journal of Personality Assessment, 54(1 & 2), 298-

    310.

    Shapiro, G., & Markoff, J. (1997). A Matter of Definition in C.W. Roberts (Ed.). Text

    Analysis for the Social Sciences: Methods for Drawing Statistical Inferences from Texts and

    Transcripts. Mahwah, NJ: Lawrence Erlbaum Associates.

    Stemler, S., and Bebell, D. (1998).An Empirical Approach to Understanding and

    Analyzing the Mission Statements of Selected Educational Institutions. Paper presented at

    the annual meeting of the New England Educational Research Organization. Portsmouth,New Hampshire. Available: ERIC Doc No. ED 442 202.

    Stigler, J.W., Gonzales, P., Kawanaka, T., Knoll, S. & Serrano, A. (1999). The TIMSSVideotape Classroom Study: Methods and Findings from an Exploratory Research Project

    on Eighth-Grade Mathematics Instruction in Germany, Japan, and the United States. U.S.

    Department of Education National Center for Educational Statistics: NCES 99-074.

    Washington, D.C.: Government Printing Office.

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    U.S. General Accounting Office (1996). Content Analysis: A Methodology for Structuring

    and Analyzing Written Material. GAO/PEMD-10.3.1. Washington, D.C. (This book can be

    ordered free from the GAO).

    Weber, R. P. (1990).Basic Content Analysis, 2nd ed. Newbury Park, CA.

    Wheelock, A., Haney, W., & Bebell, D. (2000). What can student drawings tell us about

    high-stakes testing in Massachusetts? TCRecord.org. Available: http://www.tcrecord.org/Content.asp?ContentID=10634.

    Please address all correspondence regarding this article to:

    Steve Stemler, Ph.D.

    Yale University

    Center for the Psychology of Abilities, Competencies, and Expertise (PACE Center)

    340 Edwards Street

    P.O. Box 208358New Haven, CT 06520

    E-Mail [email protected]: Content analysis; NUD*IST; Research Methods; Qualitative Analysis